Open Library API
Open Library books API: edition lookup by ISBN.
Operational
Last checked · response time 498 ms
90-day uptime
Monitoring since · 53 days of data
Past incidents
No incidents reported.
No incidents reported.
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 4m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 4m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 5m
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
No incidents reported.
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 4m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 4m
- Availability incidentEndpoint has failed 3 consecutive polls (latest: HTTP 503)
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 10m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 5m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 4m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved after 9m
- Guardian-measuredResolvedAPI: HTTP 503 · resolved (start not recorded)
Recent changes
No changes detected in 53 days of monitoring (since 2026-06-11).
Integrate
The live status, 90-day uptime figure and change history on this page are also machine-readable: embed the badge, poll the JSON, or subscribe to the feed. No key needed.
Status badge: 
Markdown embed: [](https://staging.guardiandev.ai/apis/openlibrary-api)
Machine-readable: JSON (versioned v1, CORS-enabled) · Atom feed of drift & outage events.
Guardian probes https://openlibrary.org/isbn/9780140328721.json about every 5 minutes. How Guardian measures.